The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
Many friction clutch hubs or housings for use in automatic motor vehicle transmissions are fabricated of steel because of its strength, cost, malleability and machinability. It is not ideal for all clutch applications, however, as certain configurations require specific capabilities not provided by standard steel alloys. For example, certain clutch configurations require hydraulic fluid (transmission oil) transfer under pressure from outside the clutch housing to a hydraulic clutch operator inside the housing. In such configurations, a pair of spaced apart resilient seals disposed in a stationary component of the transmission engage the rotating clutch housing and define a fluid path from the stationary component to the clutch housing and ultimately to the hydraulic operator.
In such a configuration, typical steel alloys, which may be stamped to form the clutch housing, do not exhibit sufficient hardness to withstand the constant sliding friction of the resilient seals. As the steel surface of the clutch housing wears, drag may increase and fluid leakage may occur.
One solution to this problem entails fabricating the clutch housing from separate pieces: a collar or tubular member which is forged and may thus be a relatively hard steel and a bell housing which may be stamped in a conventional fashion which may thus be softer steel. The collar which includes an outer surface which is engaged by the resilient seals is then welded to the bell housing. While this approach provides a clutch housing having the requisite hardness of the surface engaged by the seals, the manufacturing steps and expense relative to a single piece stamped housing are problematic.
Thus, it would be desirable to provide a single piece clutch housing having a hard wear surface that is fabricated of a steel alloy that may be stamped to form the housing. The present invention is so directed.